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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
ZWO 2.1mm 150° All-Sky Lens - For 1/3" Sensors

ZWO 2.1mm 150° All-Sky Lens - For 1/3" Sensors

by ZWO
SKU ZWO-LENS-2.1
$22.00 - $22.00
$22.00
$22.00 - $22.00
$22.00
Price Match Policy!
  • Focal Length: 2.1mm
  • Field of View: 150° (on 1/3" sensor)
  • Aperture: f/2.0
  • Mount: CS-Mount
  • Sensor Compatibility: 1/3" format cameras
1 in stock
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Warranty

  • Capture the Whole Sky — The ZWO 2.1mm F/2.0 All-Sky Lens

    The ZWO 1/3" 2.1mm 150° lens is built to solve a specific problem: how to capture the entire night sky in a single frame for meteor detection, cloud monitoring, and time-lapse projects. This compact CS-mount lens transforms compatible ZWO planetary cameras into dedicated all-sky monitors, giving you a constant, ultra-wide perspective of celestial events as they unfold overhead.

    A 150-Degree Perspective for All-Sky Awareness

    The core of this lens is its 2.1mm focal length, which produces an immense 150-degree field of view when paired with a 1/3" sensor camera like the ASI120. This expansive coverage is the key to its function, allowing you to monitor for sporadic fireballs, track the radiant of a meteor shower, or simply keep a continuous record of atmospheric conditions at your observing site without a tracking mount. The fast f/2.0 aperture gathers a significant amount of light, which is critical for capturing the fleeting trails of meteors against the night sky.

    Direct-Attach CS-Mount Simplicity

    Engineered with a standard CS-mount thread, this lens attaches directly to the body of many ZWO planetary cameras, replacing the standard 1.25" nosepiece. This secure, threaded connection eliminates the potential for tilt or flexure that can occur with nosepiece adapters. The result is a rigid and reliable imaging system that you can set up once and leave to run, confident in its mechanical stability. Focusing is achieved by simply rotating the lens barrel, with a locking screw to hold its position once set.

    Optimized for Small Sensors, Adaptable to Others

    This lens is optically designed to illuminate a 1/3" sensor, providing a sharp, complete circular image on cameras in that class. While it can be mounted on cameras with larger sensors, like the 1/2.9" format ASI290MM, it's important to understand the trade-off. On a larger sensor, the lens will produce a smaller image circle that does not cover the entire chip, resulting in dark corners. This is not a defect, but a consequence of using the lens beyond its intended design circle, a common practice for those who prioritize the wide field over full-frame illumination.

    Building Your Meteor Camera

    Paired with a high-sensitivity monochrome camera like the ASI290MM or ASI663MC, this lens becomes the heart of a powerful meteor observation station. The combination allows for short, rapid exposures that can be stacked into a time-lapse video or processed by software like SharpCap to automatically detect and log meteor events. For visual observers, it's a perfect tool for creating a nightly sky movie that shows passing satellites, cloud fronts, and the general rhythm of the night, providing valuable context for your imaging sessions.

    Here are some examples of cameras compatible with this lens:

    • ASI120mm
    • ASI120mc
    • ASI120mm-s
    • ASI120mc-s
    • ASI224mc
    • ASI290mm
    • ASI290mc
    • ASI462MC

  • Which ZWO cameras work best with the 2.1mm lens?

    This lens is optimized for ZWO cameras with 1/3" sensors, such as the ASI120 series. It is also commonly used with larger sensor cameras like the ASI290, ASI178, and ASI662MC, but it will produce an image circle that does not cover the entire sensor.

    Will this lens cover the full sensor of my ASI294MC Pro?

    No. The lens is designed for much smaller 1/3" format sensors. On a Micro Four Thirds sensor like the one in the ASI294, it will project a small circular image in the center of the frame with significant black space around it.

    How do I attach this lens to my ZWO camera?

    You first unscrew the 1.25" nosepiece or protective window from your camera body. The 2.1mm lens then screws directly into the camera's CS-mount adapter An IR-Cut window is recommended for color cameras.

    Is this lens good for deep-sky astrophotography?

    No, this is a special-purpose lens. Its extremely short focal length is designed for all-sky imaging, meteor capture, and weather monitoring, not for resolving details in galaxies or nebulae.

    Do I need filters with this lens?

    For color cameras, you will need to install an IR-Cut filter to achieve correct color balance, as the lens does not have one built-in. For monochrome cameras, no filter is strictly necessary unless you are trying to isolate specific wavelengths.

  • Focal Length 2.1mm
    Aperture f/2.0
    Field of View 150°
    Mount Type CS-Mount
    Sensor Compatibility 1/3" Format
    Dimensions 18.5mm x 16mm
    • ZWO 1/3

      ZWO 2.1mm 150° lens

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  • ZWO 2-Year Warranty